• International Journal of Fluid Machinery and Systems
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• 제10권1호
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• pp.86-98
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• 2017

In order to obtain high efficiency and low resistance droplet separation apparatus, axial vane type gas-liquid separators with different guide vanes were designed, and the RNG $k-{\varepsilon}$ model as well as discrete phase model (DPM) were used to investigate the flow pattern inside the separators. It was shown that the tangential velocity distribution under different guide vanes have Rankine vortex characteristics, pressure distribution exhibits a high similarity which value becomes big as the increase of the blade outlet angle and the decrease of the guide vane numbers. The increase of the guide vane numbers and the decrease of the blade outlet angle could make separation improve significantly. The separation efficiency is almost 100% when the droplet diameter is bigger than $40{\mu}m$.

• 대한기계학회논문집
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• 제12권5호
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• pp.984-991
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• 1988

본 연구에서는 유압관로에서 액주분리를 수반하는 유체 과도현상의 압력파형 에 때때로 관측되는 2단적 압력상승현상의 발생기구를 실험 및 이론적인 추론, 특성곡 선법을 사용한 수치해석을 통하여 명확히 구명함을 목적으로 한다.

• International Journal of Fluid Machinery and Systems
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• 제4권2호
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• pp.262-270
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• 2011

Experimental and numerical investigations were conducted for an internal flow in an axial flow stator of a diagonal flow fan. A corner separation near the hub surface and the suction surface of a stator blade was focused on, and further, three-dimensional vortices in separated flow were investigated by the numerical analysis. At low flow rate of 80% of the design flow rate, a corner separation of the stator between the suction surface and the hub surface can be found in both experimental and calculated results. Separation vortices are observed in the limiting streamline patterns both on the blade suction and on the hub surfaces at 80% of the design flow rate in the calculated results. It also can be observed in the streamline pattern that both vortices from the blade suction surface and from the hub surface keep vortex structures up to far locations from these wall surfaces. An attempt to explain the vortices within a three-dimensional separation is introduced by using vortex filaments.

• Bulletin of the Korean Chemical Society
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• 제17권6호
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• pp.496-498
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• 1996

Fatty alcohol ethers, nonionic surfactants which are used as general purpose emulsifiers were separated by use of water-modified carbon dioxide mobile phase in capillary supercritical fluid chromatography. Much greater peak intensities and improved separation were observed in the chromatogram with on-line modified mobile phase than with pure CO2. A simple method for the preparation of on-line modified mobile phase is also introduced.

• 한국유체기계학회 논문집
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• 제19권4호
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• pp.48-53
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• 2016

The centrifugal separator which uses gravity separation method for oil-water separation, rotating at high-speed, is one of the most commonly used device for controlling the amount of the oil in waste water collected in bilge. The IMO (International Maritime Organization) has set regulations, also known as MARPOL 73/78, for the prevention of marine pollution. In addition, DET NORSKE VERITAS (DNV) has set standards regarding the assignment of Environmental Class Notation, CLEAN or CLEAN DESIGN, of ships. One of the requirements for classification is that in addition to conforming to MARPOL 73/78, more stringent measures must be taken as well. One of these measures is to limit the oil concentration in bilge water to less than 5ppm. So in this study, an Oil-Water Separator (OWS) is used together with multiple separating plates as a filtration system to be used as an oil-water separation device. The OWS operates using centrifugal separation in which the mixture is separated by centrifugal forces. The main purpose of this paper is to present the OWS separation efficiency according to the rotation speed, mass-flow rate, the angle and the number of stacked layers of the laminated plate using Computational Fluid Dynamics (CFD). Improvements to the device will be investigated from these results.

• 유변학
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• 제1권1호
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• pp.12-19
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• 1989

Polymer fluid flow and polymerization reaction occur simultaneously during the reactive polymer processing. The viscosity and physical properties change as thereaction proceeds and the crystallization and vitrifica-tion occur as the T,,,and the Tg of the polymerizing fluid exceeds the reaction temperature within the mold.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.140-146
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• 2002

The fluid induced vibration (FIV) phenomena of a 2-D.O.F airfoil system have been investigated in low Reynolds number incompressible flow region. Unsteady flows with viscosity are computed using two-dimensional incompressible Navier-stokes code. To validate developed Navier-Stokes code, steady and unsteady flow fields around airfoil are analyzed. The present fluid/structure interaction analysis is based on the most accurate computational approach with computational fluid dynamics (CSD) and computational structural dynamics (CSD) techniques. The highly nonlinear fluid/structure interaction phenomena due to severe flow separations have been analyzed fur the low Reynolds region (R$_{N}$ =500~5000) that has a dominancy of flow viscosity. The effect of R$_{N}$ on the fluid/structure coupled vibration instability of 2-DOF airfoil system is presented and the effect of initial angle of attack on the dynamic instability are also shown.own.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.399.2-399.2
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• 2002

Capillary electrophoretic direct chiral separation method is described for the determination of the absolute configuration of chiral aromatic acids, The enantiomeric separation was achieved by capillary electrophoresis using HP $\beta$-cyclodextrin (CD) as the chiral selector. The effect of CD concentration was investigated to optimize the chiral separation and resolution. When applied to microbial culture fluid. the present method allowed positive identification of chiral aromatic acids and their chirality as well.

• 대한화학회지
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• 제46권5호
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• pp.412-429
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• 2002

(+)(18crown6)-tetracarboxylic acid ($18C6H_4$)를 퀴놀린계 항생제인 gemifloxacin을 모세관 전기영동법으로 키랄 분리하였다. Body fluid에서 퀴놀린계 항생제인 gemifloxacin의 직접적인 분석은 빠른 분석 시간, 다성분 분석등의 여러 가지 장점을 가진다. 그러나 Body fluid내의 높은 농도의 나트륨 이온은 $18C6H_4$와 강한 전하 상호작용으로 인하여 gemifoxacin과 $18C6H_4$의 상호작용을 방해한다. 키랄 선택제와 나트륨 이온 사이의 상호 작용을 줄이기 위해 완충 용액에 킬레이트 리간드 EDTA를 첨가하였다. 시료 용액에 150mM의 나트륨 이온이 존재 할 때에도 분리 효율의 향상과 이동 시간의 감소를 관찰 할 수 이었다.

• International Journal of Air-Conditioning and Refrigeration
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• 제10권3호
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• pp.138-146
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• 2002

The phenomena of energy separation in vortex tubes was investigated experimentally to see the subsidiary effect of the conductivity of tube material and cooling conditions around the outer surface of the tube. The experiment was carried out with pyrex, stainless steel and copper tubes, and the heat transfer conditions of the tubes were with insulation, without in-sulation and water cooling modes respectively The results were obtained that the hot exit fluid temperature was highly affected by a change of conductivity of a tube when the outer surface was cooled by the water, while the working fluid through the tubes was air. How-ever, the cold exit temperature was little affected by the heat transfer modes on the outer surface of the vortex tube.